Ornamental Grass Named &#39;Tift PA17&#39;

ABSTRACT

A new variety of Pennisetum alopecuroides plant named ‘Tift PA17’ produces a reduced number of seeds, making it less invasive.

Latin name of the genus and species of the plant claimed: ‘Tift PA17’ isa vegetatively propagated ornamental perennial Pennisetum cultivar ofthe genus and species Pennisetum alopecuroides.

Variety denomination: The new Pennisetum alopecuroides claimed is of thecultivar denominated ‘Tift PA17’.

BACKGROUND OF THE INVENTION

The present invention relates to a new and distinct cultivar ofPennisetum alopecuroides herein referred to as ‘Tift PA17’.

The new Pennisetum alopecuroides is a product of a planned research,evaluation, and testing program conducted by the Inventors in Tifton,Ga. The objective of the Pennisetum alopecuroides research program is tocreate a new plant cultivar with reduced seed production. This cultivaris commercially important for its superior ornamental value and low seedproduction. These and other qualities are enumerated herein.

Pedigree and history: We evaluated four unpatented morphologicallyvariable accessions maintained at Tifton, Ga. for ornamental potential:‘Tift PS989’, ‘Tift PS990’, ‘Tift PS1122’, and ‘Tift PS1123’. ‘TiftPS989’ and ‘Tift PS1122’ were selected as accessions with the mostornamental potential. Pennisetum alopecuroides accessions and cultivarsare known to produce abundant seed. Seed production in commercialornamental cultivars of Pennisetum alopecuroides tends to make thisgenus/species invasive, an undesirable trait in landscapes. Seeds fromopen pollinated ‘Tift PS1122’ plants were irradiated on 11 Nov. 2010with 20 Kr of Cobalt 60 gamma radiation. These irradiated seeds wereplanted to produce a first group of plants. In 2011, this first group ofplants were evaluated and eight of these first group of plants wereselected. These eight plants were selected as morphologically desirableornamental genotypes with reduced seed set. Open pollinated seeds wereharvested from these eight plants. These seeds from the eight selectedplants were re-irradiated on 10 Jan. 2012 with 10 Kr of Cobalt 60radiation. Only three of the eight plants produced seed that survivedthis second irradiation. The surviving seed from the three plants wereplanted to produce 142 plants, numbered consecutively from 1 to 142,that were grown in adjacent rows in a field. These 142 plants wereallowed to open pollinate. Irradiation of seeds usually results inchineras or sectors on the plants for the trait of interest. Therefore,each of the 142 plants was divided into four quadrants or sectors (a, b,c, and d) and five or more inflorescences from each quadrant wereexamined for seed sterility. Highly seed sterile plant number 125 wasselected in 2012 and became ‘Tift PA17’. ‘Tift PA17’ has been tested atTifton, Ga. in 2012, 2014, and 2015 and in Blairsville, Ga. from 2012thru 2015. Tests consisted of five and four single plant replicationsarranged in a randomized complete block experiment at Tifton, Ga. andBlairsville, Ga., respectively. Seven other experimental entries wereincluded in each test. ‘TIFT PA24’ (unpatented) was selected as a seedand pollen fertile check with desirable ornamental characteristics fromTift PS1122. ‘TIFT PA24’ also produced abundant pollen for pollinatingthe experimental seed sterile cultivars in the replicated tests to makesure that the experimental sterile cultivars would not set seed whenpollinated with pollen from another genotype.

Asexual reproduction of the new Pennisetum ‘Tift PA17’ by vegetativepropagation (single stem propagules) in a controlled environment inTifton, Ga. and Blairsville, Ga. from 2012 through 2015, has shown thatthe unique features of this new Pennisetum cultivar are stable andreproduced true to type in successive generations.

SUMMARY OF THE INVENTION

The following traits have been repeatedly observed and represent thecharacteristics of a new P. alopecuroides cultivar ‘Tift PA17’. The newcultivar ‘Tift PA17’ has not been observed under all possibleenvironmental conditions. The phenotype may vary somewhat withvariations in, for example, temperature, day-length, light intensity,soil types, and water and fertility levels without, however, anyvariance in genotype.

Throughout this specification, color names beginning with a small lettersignify that the name of that color, as used in common speech, is aptlydescriptive. Color names beginning with a capital letter designatevalues based upon the R.H.S. Colour Chart (5^(th) Edition, 2007),published by The Royal Horticultural Society, London, England.

The following traits have been repeatedly observed for the new P.alopecuroides cultivar ‘Tift PA17’ in Tifton, Ga. and Blairsville, Ga.and can be compared to P. alopecuroides, ‘TIFT PA24’ (a seed fertilegenotype with desirable ornamental characteristics):

1. ‘Tift PA17’ exhibits a vigorous growth habit.

2. ‘Tift PA17’ is highly seed sterile.

3. Inflorescence numbers for ‘Tift PA17’ are variable.

4. ‘Tift PA17’ produces variable canopy widths.

5. Inflorescence numbers of ‘Tift PA17’ vary according to season andlocation.

The new cultivar Pennisetum ‘Tift PA17’ can be compared to Pennisetumalopecuroides, ‘TIFT PA24’, a seed fertile and desirable ornamentalselection:

Plants of the new Pennisetum ‘Tift PA17’ are compared to ‘TIFT PA24’ inthe following characteristics:

1. The new cultivar ‘Tift PA17’ produces significantly fewer seeds atTifton, Ga. and Blairsville, Ga. compared to ‘TIFT PA24’.

2. The maximum inflorescences and leaf heights of the mature ‘Tift PA17’plants has been observed to be less than the maximum inflorescences andleaf heights of mature ‘Tift PA24’ plants.

3. The new cultivar ‘Tift PA17’ has been observed to have a leaf canopydiameter that was greater than that of ‘Tift PA24’, except for 2015 inTifton, Ga. (Table 3).

4. Inflorescence lengths of the new cultivar ‘Tift PA17’ range fromsignificantly longer than to approximately equal to the inflorescencelengths of ‘TIFT PA24’.

5. Leaf width of ‘Tift PA17’ leaves have been observed to be slightlynarrower than the leaf width of ‘Tift PA24’ leaves. In all but one yearof observation, the leaf length of ‘Tift PA17’ leaves was greater thanthe leaf length of ‘Tift PA24’ leaves.

The following observations, measurements, and values describe plantsgrown in Tifton, Ga. and Blairsville, Ga. In Tables 1-7, the leastsignificant difference (LSD) is set at P≤0.05 probability level. Growthdays were included in ratings. Plants were spaced 1 meter apart down therow and rows were 2 meters apart. Plants were established as single stempropagules in mid-April to mid-May and rated in September throughOctober. Data was taken from plants during year of establishment atTifton and Blairsville except 2015 data from Blairsville was taken onplants established in 2014. ‘Tift PA17’ was usually either significantlyshorter than or about equal to ‘TIFT PA24’ for height of inflorescencesand height of leaves. Canopy diameter varied for both ‘Tift PA17’ and‘TIFT PA24’ between years and locations. The canopy diameter contributesto the beauty of the long arching leaves of these selections beforeinflorescences are produced. Inflorescence number adds greatly to thebeauty of this species. Inflorescence numbers for ‘Tift PA17’ were equalto or significantly greater than for ‘TIFT PA24’ (Table 4) in all yearsexcept in 2014 at Tifton; where ‘Tift PA17’ had fewer inflorescences.However, inflorescence length for Tift PA17 tended to be significantlylonger than those of ‘TIFT PA24’ at Blairsville, but not at Tifton(Table 5). ‘PA17’ had the longest inflorescences at Blairsville; whichadds to the attractiveness of the variety. Except for 2015 in Tifton,‘Tift PA17’ had longer leaves than ‘Tift PA24’. In addition, the ‘TiftPA17’ leaves were narrower than ‘Tiff PA24’ leaves (Table 6).

The adaxial leaf color of mature leaves of ‘Tift PA17’ plants isGreen-141B, whereas inflorescence colors were Greyed Orange-165B, for‘Tift PA17’.

Seed set in ‘Tift PA17’ is significantly reduced. (Table 7).

TABLE 1 Height of inflorescence of two Pennisetum alopecuroides grasses(‘TIFT PA24’ is the seed and pollen fertile control) planted at twolocations in Georgia. Height of Inflorescence (cm) Tifton BlairsvilleEntry 2012 2014 2015 2012 2013 2014 2015 ‘PA 17’ 57 58 64 91 110 110 112PA 24 62 51 83 107 126 106 106 LSD 6 9 8 9 12 14 9 Growth Days 180 99101 178 116 130 155Plant heights were measured from ground level to top of inflorescence.The Tifton tests were planted 18 Apr. 2012, 02 June 2014, and 12 May2015 and measurements were taken 15 Oct. 2012, 09 Sep. 2014, and 21 Aug.2015, respectively. The Blairsville tests were planted 14 Apr. 2012, 16May 2013, and 15 May 2014, and measurements were taken 09 Sep. 2012, 09Sep. 2013, 22 Sep. 2014 and 24 Sep. 2015 (data taken on 2014 plants),respectively. The least significant difference at the P≤0.05 probabilitylevel.

TABLE 2 Height of leaves of six ornamental Pennisetum alopecuroidesgrasses (‘TIFT PA24’ is the seed and pollen fertile control) planted attwo locations in Georgia. Height of Leaves (cm) Tifton Blairsville Entry2012 2013 2014 2015 2012 2013 2014 2015 ‘Tift PA 17’ 78 41 41 42 53 7452 81 ‘Tift PA24’ 86 41 34 54 60 73 50 83 LSD 9 8 7 5 5 9 10 5 GrowthDays 180 170 99 101 148 116 130 155The height of leaves were measured from ground level to top of leafcanopy. The tests at Tifton were planted 18 Apr. 2012, 13 Apr. 2013, 02June 2014, and 12 May 2015 and measurements taken 5 Oct. 2012, 30 Sep.2013, 09 Sep. 2014, and 21 Aug. 2015, respectively. The Blairsvilletests were planted 14 Apr. 2012, 16 May 2013, and 15 May 2014, andmeasurements were taken 09 Sep. 2012, 09 Sep. 2013, 22 Sep. 2014 and 24Sep. 2015 (data taken on 2014 plants), respectively. The leastsignificant difference at the P≤0.05 probability level.

TABLE 3 Canopy diameter of two ornamental Pennisetum alopecuroidesgrasses (‘TIFT PA24’ is the seed and pollen fertile control) planted attwo locations in Georgia. Canopy Diameter (cm) Tifton Blairsville Entry2012 2015 2014 2015 ‘Tift PA17’ 86 76 128 153 ‘Tift PA24’ 81 98 123 136LSD 10 9 25 7 Growth Days 180 101 130 155The canopy diameter is the average diameter of the widest and thenarrowest diameter of a single plant canopy. The tests at Tifton wereplanted 18 Apr. 2012 and 12 May 2015 and measurements taken 08 Oct.2012, and 21 Aug. 2015, respectively. The tests at Blairsville wereplanted 15 May 2014 and measurements taken 22 Sep. 2014 and 24 Sep.2015(data taken on 2014 plants). The least significant difference wasset at the P≤0.05 probability level.

TABLE 4 Number of inflorescences per plant of two ornamental Pennisetumalopecuroides grasses (‘TIFT PA24’ is the seed and pollen fertilecontrol) planted at two locations in Georgia. Number of InflorescencesTifton Blairsville Entry 2012 2014 2015 2014 2015 ‘Tift PA17’ 195 83 6581 100 ‘Tift PA24’ 79 135 62 75 67 LSD 33 42 16 43 19 Growth Days 180 99101 130 155Total number of inflorescences were counted per plant. The tests atTifton were planted 18 Apr. 2012, 13 Apr. 2013, 02 June 2014, and 12 May2015 and measurements were taken on 15 Oct. 2012, 30 Sep. 2013, 09 Sep.2014, and 21 Aug. 2015, respectively. The tests at Blairsville wereplanted 14 Apr. 2012, 16 May 2013, and 15 May 2014, and measurementswere taken 09 Sep. 2012, 09 Sep. 2013, 22 Sep. 2014 and 24 Sep. 2015(data taken on 2014 plants), respectively. The least significantdifference was set at the P≤0.05 probability level.

TABLE 5 Inflorescence length of two ornamental Pennisetum alopecuroidesgrasses (‘Tift PA24’ is the seed and pollen fertile control) planted attwo locations in Georgia. Inflorescence Length (cm) Tifton BlairsvilleEntry 2012 2015 2012 2013 2014 2015 ‘Tift PA17’ 12 11.1 15 16 16 19‘Tift PA24’ 13 11.1 13 15 13 15 LSD 1 0.8 1 1 2 1.4 Growth Days 180 101178 116 130 155Inflorescence length was the mean of three inflorescences per plant. Thetests at Tifton were planted 18 Apr. 2012 and 12 May 2015 andmeasurements taken 15 Oct. 2012 and 21 Aug. 2015, respectively. Thetests at Blairsville were planted 14 Apr. 2012, 16 May 2013, and 15 May2014, and measurements taken 09 Sep. 2012, 09 Sep. 2013, 22 Sep. 2014and 24 Sep. 2015 (data taken on 2014 plants), respectively. The leastsignificant difference at the P≤0.05 probability level.

TABLE 6 Leaf characteristics of individual plants of two ornamentalPennisetum alopecuroides grasses (‘Tift PA24’ is the seed and pollenfertile control) planted at two locations in Georgia. Leaf Length (cm)Leaf Width (mm) Tifton Blairsville Tifton Blairsville Entry 2012 20152015 2012 2015 2015 ‘Tift 28.9 27.6 47 6.2 5.7 8.8 PA17’ ‘Tift 26.8 33.640.2 6.5 7.4 9.6 PA24’ LSD 5.1 3.3 10.9 1.4 0.7 1.1Leaf length (average from three culms) was measured from the leaf collarto the leaf tip of the latest fully extended leaf. Leaf width (averageof three culms) was measured in the center of the latest fully extendedleaf. The tests at Tifton were planted 18 Apr. 2012 and 12 May 2015 andmeasurements taken 15 Oct. 2012, and 21 Aug. 2015, respectively. Thetests at Blairsville were planted 15 May 2014 and measurements taken 24Sep. 2015 (data taken on 2014 plants), respectively. The leastsignificant difference was set at the P≤0.05 probability level.

TABLE 7 Seed set per inflorescence and seed germination of twoornamental Pennisetum alopecuroides grasses (‘TIFT PA24’ is the seed andpollen fertile control) planted at two locations in Georgia. Seeds perInflorescence Seed Germination—% Tifton Blairsville Blairsville Entry2013 2015 2013 2014 2015 2014 ‘Tift 0.0 0.0 2.0 0.8 0.2 34 PA17’ ‘Tift15.4 91.5 121 102 71.2 93 PA24’ LSD 0.3 0.0 26 29.4 1.3 21Seeds per inflorescence was the mean of four random inflorescences pereach replication.Seed germination tests consisted of 25 seeds from four and threedifferent plants (replications) harvested in Oct. 2014 at Tifton andBlairsville, respectively. Germination tests were conducted in April of2015 to allow seeds to go through a dormancy period and simulate fieldconditions. The Tifton tests were planted 13 Apr. 2013 and 12 May 2015and measurements taken in Oct. 2013 and 2015. The Blairsville tests wereplanted 16 May 2013, and 15 May 2014, and measurements taken 09 Sep.2013, 22 Sep. 2014 and 24 Sep. 2015 (data taken on 2014 plants),respectively. The least significant differences were set at the P≤0.05probability level.

TABLE 8 Summary of morphological characteristics of two Pennisetumalopecuroides cultivars. Trait ‘TIFT PA24’ ‘Tift PA17’ Matureinflorescence 51-126 cm 57-110 cm height Mature leaf height 34-86 cm41-81 cm Diameter of plant 81-135 cm 76-153 cm canopy Inflorescencelength 11.1-15 cm 11.1-19 cm Number of 62-135 65-195 Inflorescences perplant Leaf width 7.4-9.6 mm 5.7-8.8 mm Leaf length 26.8-40.2 cm 27.6-47cm Adaxial leaf surface Glabrous Glabrous trichomes Abaxial leaf surfaceGlabrous Glabrous trichomes Leaf blade margin Less than 0.5 mm Less than0.5 mm trichome length long long Leaf collar trichomes Dense, 2 mm longMedium density, 2 mm long Sheath trichomes Margins sparse, Marginssparse, less 1 mm long than 1 mm long Ligule Yes. Yes Ligule trichomesSparse, less than 1 mm Glabrous long Sheath trichomes Sparse, 1 mm longSparse on margins, less than 1 mm long Floret length 5-6 mm 5 mm Bristlelength 6-19 mm 5-26 mm surrounding florets

BRIEF DESCRIPTION OF THE FIGURES

The accompanying colored photographs illustrate the overall appearanceand distinct characteristics of the new cultivar of Pennisetum ‘TiftPA17’. The colors in the photographs are as close as possible with thephotographic and printing technology utilized.

Certain characteristics of this variety, such as growth and color, maychange with changing environmental conditions (e.g., light, temperature,moisture, nutrient availability, or other factors). Color descriptionsand other terminology are used in accordance with their ordinarydictionary descriptions, unless the context clearly indicates otherwise.Color designations are made with reference to The Royal HorticulturalSociety (R.H.S.) Colour Chart (5^(th) edition, 2007).

FIG. 1 is a photograph of a ‘Tift PA17’ plant in landscape (year ofestablishment) in Union County, Ga.

FIG. 2 is a photograph of ‘Tift PA17’ plants growing in research plots(two year old plants) in Union County, Ga.

DETAILED DESCRIPTION

The new cultivar ‘Tift PA17’ is a vigorous perennial at Blairsville, Ga.(USDA Zone 7a). The new cultivar ‘Tift PA17’ survived 90, 95, and 101days below 0° C. and low temperatures of −9,-29, and −17° C. for thewinters of 2012/2013, 2013/2014, and 2014/2015, respectively atBlairsville, Ga.

All data are from plants established as single stem propagules inmid-April to mid-May and rated in September through October, except 2015data from Blairsville, Ga. was collected from plants planted in 2014.

-   Plant:    -   -   Mature inflorescence height.—57-110 cm.        -   Mature leaf height.—41-81 cm.        -   Diameter of plant canopy.—76-153 cm.        -   Inflorescence length.—11.1-19 cm.        -   Number of inflorescences per plant.—65-195.        -   Number of culms per plant.—Typically about the same as the            number of inflorescences per plant (Table 4) because most of            the major culms produce an inflorescence.-   Leaf:    -   -   Leaf width.—5.7-8.8 mm.        -   Leaf length.—27.6-47 cm.        -   Adaxial leaf surface trichomes.—Glabrous.        -   Abaxial leaf surface trichomes.—Glabrous.        -   Leaf blade margin trichome length.—Less than 1 mm long.        -   Leaf collar trichomes.—Medium density, 2 mm long.        -   Sheath trichomes.—Margin sparse, less than 1 mm long.        -   Ligule.—Yes.        -   Ligule trichomes.—Glabrous.        -   Sheath trichomes.—Sparse on margins, less than 1 mm long.        -   Adaxial leaf color.—Green 141B.        -   Abaxial leaf color.—Green 139D.        -   Inflorescence color.—Greyed Orange 165B.

Although (rust (Puccinia substriata), leaf spot (Pyricularia grisea),and Helminthosporium sp. leaf spot are common diseases for Pennisetum inTifton, Ga. due to its humid and warm climate; to date, ‘Tift PA17’ hasnot presented any disease symptoms.

No pest susceptibility has been observed for ‘Tift PA17’.

Hardiness: ‘Tift PA17’ has vigorously survived 64, 97 and 96 days below0° C. and lowest temperatures of −12° C., −18° C. and −17° C., in 2012,2014, and 2015, respectively in Blairsville, Ga.

1. A new and distinct cultivar of the Pennisetum alopecuroides plantnamed ‘lift PA17’, as illustrated and described herein.